Field of the Invention
The present invention relates to wireless communication and, most particularly, to a method and apparatus for outputting supplementary content from a wireless fidelity (Wi-Fi) display (WFD).
Related Art
Although the performance of mobile devices has evolved remarkably to be considered as the equivalent of personal computers (PCs), the mobile device still has its limitations in screen size. Most particularly, since portability is one of the most important features of the mobile device, it marginal line for screen size is said to be equal to 6 inches. However, for users who enjoy viewing multi-media content, a 6-inch display may still be considered to be a small screen.
Accordingly, extensive research is being carried out for developing a technology enabling users to watch images (or video) that were viewed in the mobile device through large-sized television (TV) screens or monitor screens. This technology may also be expressed by using the term wireless display transmission technology. The wireless display transmission technology may be broadly divided into content transmission and mirroring (screen casting). Instead of directly transmitting the display screen of the mobile device as it is, content transmission should be associated with Video on Demand (VOD) services. More specifically, content transmission is a method of sending images (or video) via signal, and mirroring is a method of sending a content filed to a remote device via streaming in order to show (or display) the same content once again through a large-sized screen, such as a TV screen.
Just as implied in the term itself, mirroring (screen casting) corresponds to a method of simultaneously showing a screen that is displayed on a mobile device as though it is reflected on a mirror. This is similar to a method of projecting a computer screen through a projector, when performing a presentation by establishing a wired connection, such as D-Subminiature (D-sub) (RGB), Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI). The mirroring method is advantageous in that it can wirelessly transmit pixel information of an original screen without modification in real-time without being dependent on a specific service.
WiFi Miracast is being researched as a wireless display transmission technology using Wi-Fi. Miracast is a wireless image (or video) transmission standard as well as a wireless display transmission technology. Miracast is a type of mirroring (screen casting) technology, wherein the display screen and sound are compressed and outputted to a wireless LAN and then the compressed display screen and sound are decompressed in a dongle or an all-in-one receiver, thereby being displayed on the screen.